The media resource indicated by the src attribute or assigned media provider object was not suitable
NotSupportedError: The media resource indicated by the src attribute or assigned media provider object was not suitable.

In chrome setting the video dom node's src attribute to the empty string ( "" ) frees the memory associated with the video node. This doesn't work in FF in versions 16.0.1 through to today's current nightly build 19.0a1. The nightly build has the attribute mozSrcObject available on the video node which someone suggests you can set to null but that does not seem to work either. I have also tried removing the nodes from the DOM in hopes that they get garbage collected but that doesn't work either

Location of the media resource
The src content attribute on media elements gives the address of the media resource (video, audio) to show. The attribute, if present, must contain a valid non-empty URL potentially surrounded by spaces.
If a src attribute of a media element is set or changed, the user agent must invoke the media element's media element load algorithm. (Removing the src attribute does not do this, even if there are source elements present.)
It sounds like setting the src to an empty value or removing it won't fire the media element load algorithm. I'd suggest trying a load() call afterward. If you can force it to go through the resource selection algorithm, then it will hit this step:
Otherwise the media element has neither a src attribute nor a source element child: set the networkState to NETWORK_EMPTY, and abort these steps; the synchronous section ends.
Of course, I'm just guessing. Hope it helps.